Method for mounting a guide apparatus

Abstract

A method of mounting a guide apparatus of a large hydraulic machine with a vertical axis of rotation and wherein the axes of the guide blades extend vertically as well. The method includes the following steps: assembling an assembly with at least the upper guide wheel ring or the turbine cover and all the guide blades of the guide apparatus. This assembly does not take place in the machine shaft and the guide blades are mounted in a suspended manner, lowering the guide blades to mutually different height levels within the assembly such that the lowered guide blades can be displaced upwardly, installing the lower guide wheel ring in the machine shaft, and installing the assembly in the machine shaft by continuous lowering, wherein the guide blades present in the assembly are successively inserted into the openings provided in the lower guide wheel ring.

Claims

1. A method for mounting a guide apparatus of a large hydraulic machine with a vertical rotational axis in a machine shaft, the method comprising: assembling a subassembly that includes at least an upper guide wheel ring and all guide vanes of the guide apparatus, the assembling step being carried out remotely of the machine shaft; mounting the guide vanes in a suspended manner with axes of the guide vanes extending vertically; prior to lowering the subassembly into the machine shaft, lowering the guide vanes to differing heights in relation to each other inside the subassembly so that the lowered guide vanes are displaceably in an upward direction; providing a lower guide wheel ring with openings for insertion of the guide vanes and installing the lower guide wheel ring in the machine shaft; and continuously lowering the subassembly into the machine shaft for installing the subassembly in the machine shaft and, during the lowering, successively inserting the guide vanes that are disposed in the subassembly into the openings provided in the lower guide wheel ring.

2. The method for mounting a guide apparatus according to claim 1, wherein the subassembly further includes a control mechanism of the guide apparatus.

3. The method for mounting a guide apparatus according to claim 1, which comprises lowering two guide vanes of the guide vanes in each case to a common height.

4. The method for mounting a guide apparatus according to claim 1, which comprises lowering three guide vanes of the guide vanes in each case to a common height.

5. The method for mounting a guide apparatus according to claim 1, which comprises lowering four guide vanes of the guide vanes in each case to a common height.

6. The method for mounting a guide apparatus according to claim 1, wherein the step of lowering the guide vanes comprises using spindles for lowering the guide vanes.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

(1) FIG. 1 is a schematic view of a large hydraulic machine with a guide apparatus in a machine shaft;

(2) FIGS. 2-6 are schematic views illustrating an installation sequence according to the invention, wherein guide vanes are installed between lower and upper guide wheel rings.

DESCRIPTION OF THE INVENTION

(3) FIG. 1 shows a schematic view of a large hydraulic machine 2 and a guide apparatus 1 mounted in a machine shaft 3. An installation sequence for installing the guide vanes 6 in the turbine rotor is illustrated in FIG. 2 through FIG. 6.

(4) After the lower guide wheel ring 5 has been installed in the machine shaft 3, and possibly also the turbine rotor wheel, the preassembled subassembly is transported with the powerhouse crane to the machine shaft 3, positioned and aligned above the lower guide wheel ring 5, and finally lowered. In the process, the individual guide vanes 6 have to be threaded by their lower spigots 7 into the associated openings 8 of the lower guide wheel ring 5. This process entails several technical difficulties since small deviations (within the scope of the normal manufacturing tolerances) from the ideal arrangement of the guide vanes already make it almost impossible for all the guide vane spigots 7 to be threaded simultaneously into the associated openings 8 of the lower guide wheel ring 5. According to the invention, this problem is solved as follows: before the subassembly is received for installing in the machine shaft 3, the guide vanes 6, suspended in the upper guide wheel ring 4 or in the turbine cover, are lowered so that the lower edge of the lower guide vane spigots 7 comes to lie in each case at a different height. In this case, the term height refers to the position in the direction of the guide vane axes (which in the installed state all extend parallel to the turbine rotational axis) and relative to the upper guide wheel ring 4 or to the turbine cover. The lower edges of the guide vane spigots 7 therefore lie at different heights in each case when each imaginary plane perpendicular to the guide vane axes, which extends through a lower edge of a guide vane spigot 7, just touches this one lower edge and no other lower edge of another guide vane spigot 7.

(5) The described lowering of the guide vanes can for example by carried out by suitable spindles which allow an axial adjustment of the guide vanes. It is clear that the installation of the guide vanes into the subassembly and the lowering of these can be carried out just as easily in one step.

(6) If the subassembly is now lowered over the lower guide wheel ring 5, then first of all only one guide vane spigot 7, specifically the lowermost guide vane spigot 7, has to be inserted into the provided opening 8 of the guide wheel ring 5. With further lowering, the remaining guide vane spigots 7 are inserted in succession, wherein the already inserted spigot ensures an increasingly better guiding of the entire subassembly. In this way, only one spigot 7 is ever inserted at one point in time, which makes the installation of the subassembly appreciably easier.

(7) Naturally, insertion aids (e.g. two-part rings with insertion bevels) can also be used in addition for better threading in.

(8) In practice, it has become apparent that the method also functions well when two or three or four guide vane spigots always come to lie at the same height. In other words, in this case two or three or four spigots always have to be threaded in at the same time when lowering the subassembly. This functions particularly well when the spigots which lie at the same height are as far apart as possible since in this way after threading in the first group of spigots which lie at the same height a very good guiding for further threading in is already achieved. When using two groups, the spigots which lie at the same height should therefore always be selected opposite each other, in the case of three groups should be in an arrangement which forms an approximately equilateral triangle, and in the case of four groups should be in a cross-shaped or approximately square arrangement. If the number of guide vanes does not permit a perfect distribution into the desired groups, the remaining guide vanes can be threaded in any arrangement without any problems at the very end.

(9) It may additionally be mentioned that the described lowering has to be carried out so that an axial sliding of the guide vanes in an upward direction is possible because when the lowermost guide vane spigots are completely threaded into the lower guide wheel ring a further lowering of the subassembly can only be carried out when these completely inserted guide vanes can be displaced in an upward direction relative to the upper guide wheel ring or turbine cover. After the subassembly has been completely lowered, all the guide vanes are therefore located at the same height again. This precondition can be brought about, however, without any problem using the mentioned spindles.

(10) If it is conceded that the threading in of the subassembly requires a slightly longer use of the powerhouse crane, by means of the method according to the invention the availability of the powerhouse crane for other lifting operations compared with the method according to the prior art is significantly increased overall and therefore the installation time of the entire power plant is curtailed.